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221.
西藏尼玛5.6级地震房屋震害特征分析 总被引:1,自引:0,他引:1
2009年7月24日西藏尼玛发生了5.6级地震,该地震的宏观震中位于那曲地区尼玛县西南军仓乡与阿里地区错勤县磁石乡之间,极震区烈度为7度。本文对该地震进行了现场考察,分析了灾区各类房屋建筑的震害特征及其破坏原因,并对该地区房屋的防震减灾研究提出了建议。 相似文献
222.
223.
Xiaoxin Cao Xia Huang Xiaoyuan Zhang Peng Liang Mingzhi Fan 《Frontiers of Environmental Science & Engineering in China》2009,3(3):307-312
Current methods for testing the electricity generation capacity of isolates are time- and labor-consuming. This paper presents
a rapid voltage testing system of exoelectrogenic bacteria called Quickscreen, which is based on a microliter microbial fuel
cell (MFC). Geobacter sulfurreducens and Shewanella baltica were used as the model exoelectrogenic bacteria; Escherichia coli that cannot generate electricity was used as a negative control. It was found that the electricity generation capacity of
the isolates could be determined within about five hours by using Quickscreen, and that its time was relatively rapid compared
with the time needed by using larger MFCs. A parallel, stable, and low background voltage was achieved using titanium as a
current collector in the blank run. The external resistance had little impact on the blank run during the initial period.
The cathode with a five-hole configuration, used to hydrate the carbon cathode, gave higher cathode potential than that with
a one-hole configuration. Steady discharge and current interrupt methods showed that the anode mostly contributed to the large
internal resistance of the Quickscreen system. However, the addition of graphite felt decreased the resistance from 18 to
5 kΩ. This device was proved to be useful to rapidly evaluate the electricity generation capacity of different bacteria. 相似文献
224.
不同剂量的酒糟对盐碱土壤改良的作用 总被引:1,自引:0,他引:1
研究以松嫩平原大庆地区盐碱地为研究对象,对不同盐渍化程度的土壤施用不同剂量的酒糟,进行盐碱土改良技术研究。通过对施用不同剂量的土壤改良基质材料的土壤化学性质的分析对比,筛选出了适宜不同盐渍化程度的土壤改良基质材料的剂量。 相似文献
225.
污泥资源化是污泥处置的发展趋势,以脱水污泥为主料,添加适量粉煤灰和粘土,制备生物膜载体填料是实验研究的主要内容。实验表明,污泥使用量为70%、粉煤灰和粘土各15%时,烧成温度为1000±25℃、保温时间为40min,烧制的填料抗压强度能达到25mpa、吸水率17%;用于药厂废水处理测试,在常温下的化学需氧量(CODCr)的平均去除率为74.0%、悬浮物(SS)的去除率为54.1%。使用扫描电镜、显微镜像检测,分析了填料烧制中孔隙形成机理、填料外貌、表面微孔结构等。实验表明,以污泥代替天然原料,在一定条件下可以烧制成填料,并能用作污水处理中生物膜载体。 相似文献
226.
文章在系统介绍超高效液相色谱技术(UPLC^TM)工作原理的基础上,总结了UPLC^TM系统在分离度、分析速度、灵敏度等方面的先进性,并以三种污染物(有机酚、氨基甲酸酯类农药、硝基苯)的UPLC^TM分析结果为、例对其在环境监测领域的应用进行了说明,以期为丰富和改进环境分析手段提供参考。 相似文献
227.
228.
Evaluation of mercury speciation and removal through air pollution control
devices of a 190 MW boiler 总被引:1,自引:0,他引:1
Chengli Wu Yan Cao Zhongbing Dong Chinmin Cheng Hanxu Li Weiping Pan 《环境科学学报(英文版)》2010,22(2):277-282
Air pollution control devices (APCDs) are installed at coal-fired power plants for air pollutant regulation. Selective catalytic reduction
(SCR) and wet flue gas desulfurization (FGD) systems have the co-benefits of air pollutant and mercury removal. Configuration
and operational conditions of APCDs and mercury speciation a ect mercury removal e ciently at coal-fired utilities. The Ontario
Hydro Method (OHM) recommended by the U.S. Environmental Protection Agency (EPA) was used to determine mercury speciation
simultaneously at five sampling locations through SCR-ESP-FGD at a 190 MW unit. Chlorine in coal had been suggested as a factor
a ecting the mercury speciation in flue gas; and low-chlorine coal was purported to produce less oxidized mercury (Hg2+) and more
elemental mercury (Hg0) at the SCR inlet compared to higher chlorine coal. SCR could oxidize elemental mercury into oxidized
mercury when SCR was in service, and oxidation e ciency reached 71.0%. Therefore, oxidized mercury removal e ciency was
enhanced through a wet FGD system. In the non-ozone season, about 89.5%–96.8% of oxidized mercury was controlled, but only
54.9%–68.8% of the total mercury was captured through wet FGD. Oxidized mercury removal e ciency was 95.9%–98.0%, and there
was a big di erence in the total mercury removal e ciencies from 78.0% to 90.2% in the ozone season. Mercury mass balance was
evaluated to validate reliability of OHM testing data, and the ratio of mercury input in the coal to mercury output at the stack was from
0.84 to 1.08. 相似文献
229.
Variations between rice cultivars in iron and manganese plaque on roots and
the relation with plant cadmium uptake 总被引:4,自引:0,他引:4
To understand certain mechanisms causing variations between rice cultivars with regard to cadmium uptake and tolerance, pot soil
experiments were conducted with two rice cultivars of di erent genotypes under di erent soil Cd levels. The relationships between
plant Cd uptake and iron/manganese (Fe/Mn) plaque formation on roots were investigated. The results showed that rice cultivars
di ered markedly in Cd uptake and tolerance. Under soil Cd treatments, Cd concentrations and accumulations in the cultivar Shanyou
63 (the genotype indica) were significantly higher than those in the cultivar Wuyunjing 7 (the genotype japonica) (P < 0.01, or P <
0.05), and Shanyou 63 was more sensitive to Cd toxicity than Wuyunjing 7. The di erences between the rice cultivars were the largest
at relatively low soil Cd level (i.e., 10 mg/kg). Fe concentrations in dithionite-citrate-bicarbonate root extracts of Shanyou 63 were
generally lower than that of Wuyunjing 7, and the di erence was the most significant under the treatment of 10 mg Cd/kg soil. The
results indicated that the formation of iron plaque on rice roots could act as a barrier to soil Cd toxicity, and may be a “bu er” or a
“reservoir” which could reduce Cd uptake into rice roots. And the plaque may contribute, to some extent, to the genotypic di erences
of rice cultivars in Cd uptake and tolerance. 相似文献
230.
固定化微生物技术处理城市微污染河水研究 总被引:2,自引:0,他引:2
将陶粒、功能化聚氨酯泡沫(FPUFS)、阿科蔓柔性填料、人工水草等4种不同载体与高效复合菌剂BP35应用于曝气生物滤池(BAF)构成固定化曝气生物滤池(G-BAF),研究固定化微生物技术对城市微污染河水的净化效果.4种G-BAF对NH4+-N、叶绿素和浊度的去除率分别为83.0%~89.0%、77.5%~89.0%和84.4%~95.2%,均大于对COD、UV254和TP的去除效果.FPUFS含有羟基、环氧基和酰胺基等反应性基团,对酶和微生物的负载量大,因此FPUFS-G-BAF对污染物的去除效率高于其余3种G-BAF.水力停留时间(HRT)对4种G-BAF去除NH4+-N的影响均不显著,而对COD的去除效果影响较大.当溶解氧(DO)浓度由2 mg/L升至4 mg/L时,4种G-BAF对COD和NH4+-N的去除率分别提高了11.9%~18.0%和12.7%~16.1%.GC-MS分析结果表明,G-BAF工艺能有效地将河水中分子质量较大的难降解有机物降解为小分子物质. 相似文献